From bef0f66b67393efa1d10ec1d9d98c490f62d167b Mon Sep 17 00:00:00 2001
From: haerong22 <haerong22@naver.com>
Date: Tue, 5 Jul 2022 03:11:52 +0900
Subject: [PATCH] #11 spring batch: SimpleFlow ex

---
 .../basic/flow/SimpleFlowExConfiguration.java |   2 +-
 .../flow/SimpleFlowExConfiguration2.java      | 111 ++++++++++++++++++
 2 files changed, 112 insertions(+), 1 deletion(-)
 create mode 100644 spring-batch/basic/src/main/java/io/springbatch/basic/flow/SimpleFlowExConfiguration2.java

diff --git a/spring-batch/basic/src/main/java/io/springbatch/basic/flow/SimpleFlowExConfiguration.java b/spring-batch/basic/src/main/java/io/springbatch/basic/flow/SimpleFlowExConfiguration.java
index 347ac674..b2a7a012 100644
--- a/spring-batch/basic/src/main/java/io/springbatch/basic/flow/SimpleFlowExConfiguration.java
+++ b/spring-batch/basic/src/main/java/io/springbatch/basic/flow/SimpleFlowExConfiguration.java
@@ -12,7 +12,7 @@ import org.springframework.batch.repeat.RepeatStatus;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 
-@Configuration
+//@Configuration
 @RequiredArgsConstructor
 public class SimpleFlowExConfiguration {
 
diff --git a/spring-batch/basic/src/main/java/io/springbatch/basic/flow/SimpleFlowExConfiguration2.java b/spring-batch/basic/src/main/java/io/springbatch/basic/flow/SimpleFlowExConfiguration2.java
new file mode 100644
index 00000000..cb8f58e1
--- /dev/null
+++ b/spring-batch/basic/src/main/java/io/springbatch/basic/flow/SimpleFlowExConfiguration2.java
@@ -0,0 +1,111 @@
+package io.springbatch.basic.flow;
+
+import lombok.RequiredArgsConstructor;
+import org.springframework.batch.core.Job;
+import org.springframework.batch.core.Step;
+import org.springframework.batch.core.configuration.annotation.JobBuilderFactory;
+import org.springframework.batch.core.configuration.annotation.StepBuilderFactory;
+import org.springframework.batch.core.job.builder.FlowBuilder;
+import org.springframework.batch.core.job.flow.Flow;
+import org.springframework.batch.core.launch.support.RunIdIncrementer;
+import org.springframework.batch.repeat.RepeatStatus;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+@RequiredArgsConstructor
+public class SimpleFlowExConfiguration2 {
+
+    private final JobBuilderFactory jobBuilderFactory;
+    private final StepBuilderFactory stepBuilderFactory;
+
+    /*
+        SimpleFlow
+
+        FlowBuilder
+        - Step, Flow, JobExecutionDecider 등 타입에 따라 다른 State 저장
+        - StepState, FlowState, DecisionState
+
+        StateTransition
+        - State state    : 현재 State
+        - String pattern : on() Transition
+        - String next    : 다음 State
+
+        - SimpleFlow 를 구성하고 있는 모든 Step 들이 Transition 에 따라 분기되어 실행
+        - SimpleFlow 내 SimpleFlow 를 2중, 3중으로 중첩해서 구성할 수 있다.
+        - Transition 은 구체적인 것 부터 그렇지 않은 순서로 적용 된다.
+
+        State
+        - Step, Flow, JobExecutionDecider 의 각 요소들을 저장
+        - Flow 를 구성하면 내부적으로 생성되어 transition 과 연동
+        - handle() 메소드 실행 수 FlowExecutionState 반환
+            - on(pattern) 의 pattern 값과 매칭여부 판단
+            - 마지막 실행 상태가 FlowJob 의 최종 상태가 됨
+        - 현재 State 실행이 완료되면 다음 State 실행
+        - 실행 순서는 순차적 개념이 아닌 설정 및 조건에 따라 결정
+        - State 가 null 이거나 실행 불가능한 상태면 종료
+
+        - SimpleFlow 는 StateMap 에 저장되어 있는 모든 State 들의 handle 메소드를 호출해서 모든 Step 들이 실행 되도록 한다.
+        - SimpleFlow 는 현재 호출되는 State 가 어떤 타입인지와 상관없이 handle 메소드를 실행하고 상태값을 얻어온다.(상태패턴)
+        - StateMap 은 StateTransition 객체로부터 State 객체의 정보를 참조해서 매핑함.
+
+     */
+    @Bean
+    public Job batchJob() {
+        return jobBuilderFactory.get("batchJob")
+                .incrementer(new RunIdIncrementer())
+                .start(step1())
+                    .on("COMPLETED")
+                    .to(step2())
+                .from(step1())
+                    .on("FAILED")
+                    .to(flow())
+                .end()
+                .build();
+    }
+
+    @Bean
+    public Flow flow() {
+
+        FlowBuilder<Flow> flowBuilder = new FlowBuilder<>("flow1");
+
+        flowBuilder
+                .start(step2())
+                .on("*")
+                .to(step3())
+                .end();
+
+        return flowBuilder.build();
+    }
+
+    @Bean
+    public Step step1() {
+        return stepBuilderFactory.get("step1")
+                .tasklet((contribution, chunkContext) -> {
+                    System.out.println("step1 was executed");
+                    throw new RuntimeException("step2 was failed");
+//                    return RepeatStatus.FINISHED;
+                })
+                .build();
+    }
+
+    @Bean
+    public Step step2() {
+        return stepBuilderFactory.get("step2")
+                .tasklet((contribution, chunkContext) -> {
+                    System.out.println("step2 was executed");
+                    return RepeatStatus.FINISHED;
+                })
+                .build();
+    }
+
+    @Bean
+    public Step step3() {
+        return stepBuilderFactory.get("step3")
+                .tasklet((contribution, chunkContext) -> {
+                    System.out.println("step3 was executed");
+                    return RepeatStatus.FINISHED;
+                })
+                .build();
+    }
+}